Kotelevskaya’s ordeal started a decade ago at a basketball game in her native Kazakhstan, when a cheering fan accidentally hit her in the jaw, according to Sennik. Thinking the persistent swelling stemmed from a cancerous tumor, doctors put Kotelevskaya through a grueling radiation treatment that impaired her ability to eat and talk, according to her American doctors.

She dropped to 79 pounds, lost her job and her husband and eventually became homeless as a result of the treatment for a tumor she never had, according to Sennik. She was convinced she would die from stage IV cancer until Sennik tracked her down in 2012 and insisted she seek help in the United States.

The cousins were close growing up in Ukraine before the break-up of the former Soviet Union but hadn’t seen each other since 1986, according to Sennik. They lost touch when she moved to Kazakhstan, though Sennik, who is now an American citizen, said he spent 25 years searching for Kotelevskaya.

“She probably had a benign cyst on the jawbone, which a lot of people have, where the bone is weak,” said Little. “Someone fell on her and when her jaw cracked, they saw the cyst and did a biopsy to see if it was cancer. If you don’t see this often or a pathologist doesn’t know it, very often it can be mistaken for cancer under the microscope.”

The inside of Kotelevskaya's mouth, the jaw bone and outside cheek and neck were heavily radiated, according to Little.

“A lot of the tissue died," he said. "She has a hole in her check and no jaw bone.”

Courtesy of Oleg Sennik

PHOTO: Lessya Kotelevskaya and Erik on a trip to Chicago.

Today, Little will remove the dead tissue, then take part of Kotelevskaya’s leg bone and move it to her face. He will use the skin and blood vessels attached to the bone as a new inside mouth and cut the bone to make a jaw that will attach with screws and a titanium plate.

Kotelevskaya is expected to spend three weeks in the hospital recuperating. The first 72 hours will be critical, according to Little, because of the risk of stroke, which could undo all the reconstruction.

Sennik said the biggest surprise for Kotelevskaya has been all the attention she has received from Americans since ABC News first reported her story last year.

“People recognize her in Starbucks and buy her coffee,” he said. “She went to the grocery store and people stepped out of line and gave her flowers. She stood there crying. She had never had that before.”

“She is so grateful because people have been so wonderful,” Sennik added. “When she got her driver’s license, people recognized her when she had her picture taken.”

Kotelevskaya has been learning some English, according to Sennik. She was initially taking English classes but had to drop out because of pain from her preliminary surgeries. Her fellow students chipped in and bought her the textbook so she could learn from home, he said.